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Which Honeywell aquastat?

I have just bought a house with an oil fired, hot water boiler. It has 3 zones, controlled by zone valves, one of them being for the Phase 3 hot water tank. When any zone valve opens, the signal from the aquastat to the Taco circulator is intermittent....sometimes there is power to the circulator briefly, sometimes not at all. If there is power to the circulator, I will hear a click in the aquastat after a short period and power stops to the circulator. Not being sure if there was a resistance issue within the circulator, I disconnected the wires to it. But the problem still occurs. I thought it was possible there was some type of "safety" within the aquastat which would kick in in case of excess amperage draw from the Taco. It has a Honeywell, but there are no #s on it. It appears to be an L8124....but I'm not sure if it's an A, B, C, or M. To top it off, the plumbing shop asked me if I knew the 4 digit suffix also. Does anyone out there know which is the correct Honeywell replacement unit I shoud ask for?

Witch Honeywell Aquastat?

Read the site rules please no DIY advice given on this site do to many reasons liablility being one of them
if youre a contractor or an HVAC trades man get youre post count up and register for a pro member ship .
in the pro sections you can ask this kind of thing.

Originally Posted by kzikyoshi

I have just bought a house with an oil fired, hot water boiler. It has 3 zones, controlled by zone valves, one of them being for the Phase 3 hot water tank. When any zone valve opens, the signal from the aquastat to the Taco circulator is intermittent....sometimes there is power to the circulator briefly, sometimes not at all. If there is power to the circulator, I will hear a click in the aquastat after a short period and power stops to the circulator. Not being sure if there was a resistance issue within the circulator, I disconnected the wires to it. But the problem still occurs. I thought it was possible there was some type of "safety" within the aquastat which would kick in in case of excess amperage draw from the Taco. It has a Honeywell, but there are no #s on it. It appears to be an L8124....but I'm not sure if it's an A, B, C, or M. To top it off, the plumbing shop asked me if I knew the 4 digit suffix also. Does anyone out there know which is the correct Honeywell replacement unit I shoud ask for?